1. Field of the Invention
The present invention relates to a contact image sensor unit and an image reader using the contact image sensor unit.
2. Description of the Related Art
In an image sensor unit with light sources installed at the respective opposite ends of a light guide in a longitudinal direction thereof (main scanning direction), leakage light may result from, for example, a variation in atmospheric temperature and/or atmospheric humidity.
Thus, an image reader (image sensor) described in Japanese Laid-Open Patent Publication No. 2004-146870 has been proposed.    Patent Document 1    Japanese Laid-Open Patent Publication No. 2004-146870
However, disadvantageously, the image sensor described in Japanese Laid-Open Patent Publication No. 2004-146870 has an increased size owing to a light guide cover provided therein to cover the light guide. For an image sensor without a light guide cover, additional components are required, disadvantageously leading to increased costs.
Furthermore, the image sensor may suffer a crack or the like when the light guide expands or contracts as a result of, for example, a variation in atmospheric temperature and/or atmospheric humidity.